poj 2240

#include<iostream>
#include<cstring>
using namespace std;
double map[111][111];
char s[33][111];
int n;
int get(char s1[])
{
    for(int i=1;i<=n;i++)
        if(strcmp(s[i],s1)==0) return i;
}
bool floyd()
{
    int i,j,k;
    for(k=1;k<=n;k++)
    {
        for(i=1;i<=n;i++)
            for(j=1;j<=n;j++)
                if(map[i][k]*map[k][j]>map[i][j])
                    map[i][j]=map[i][k]*map[k][j];
    }
    for(i=1;i<=n;i++)
        if(map[i][i]>1) return true;
    return false;
}
int main()
{
    int i,m;
    double rate;
    char s1[111],s2[111];
    int cas=0;
    while(scanf("%d",&n)!=EOF)
    {
        cas++;
        if(n==0) break;
        memset(map,0,sizeof(map));
        for(i=1;i<=n;i++)
            cin>>s[i];
        cin>>m;
        while(m--)
        {
            cin>>s1>>rate>>s2;
            int u=get(s1);
            int v=get(s2);
            map[u][v]=rate;
        }
        if(floyd())
            printf("Case %d: Yes\n",cas);
            
        else printf("Case %d: No\n",cas);
    }
    return 0;
}